[LayoutNG] Switch NGBreakToken to being RefCounted.

third_party/WebKit/Source/core/layout/ng/ng_physical_box_fragment.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef NGPhysicalBoxFragment_h
 #define NGPhysicalBoxFragment_h
 
 #include "core/CoreExport.h"
 #include "core/layout/ng/ng_physical_fragment.h"
 #include "core/layout/ng/ng_units.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Optional.h"
 
 namespace blink {
 
 struct NGFloatingObject;
 
 class CORE_EXPORT NGPhysicalBoxFragment final : public NGPhysicalFragment {
  public:
   // This modifies the passed-in children vector.
-  NGPhysicalBoxFragment(
-      LayoutObject* layout_object,
-      NGPhysicalSize size,
-      NGPhysicalSize overflow,
-      Vector<RefPtr<NGPhysicalFragment>>& children,
-      Vector<Persistent<NGFloatingObject>>& positioned_floats,
-      const WTF::Optional<NGLogicalOffset>& bfc_offset,
-      const NGMarginStrut& end_margin_strut,
-      NGBreakToken* break_token = nullptr);
+  NGPhysicalBoxFragment(LayoutObject* layout_object,
+                        NGPhysicalSize size,
+                        NGPhysicalSize overflow,
+                        Vector<RefPtr<NGPhysicalFragment>>& children,
+                        Vector<Persistent<NGFloatingObject>>& positioned_floats,
+                        const WTF::Optional<NGLogicalOffset>& bfc_offset,
+                        const NGMarginStrut& end_margin_strut,
+                        RefPtr<NGBreakToken> break_token = nullptr);
 
   const Vector<RefPtr<NGPhysicalFragment>>& Children() const {
     return children_;
   }
 
   // List of positioned float that need to be copied to the old layout tree.
   // TODO(layout-ng): remove this once we change painting code to handle floats
   // differently.
   const Vector<Persistent<NGFloatingObject>>& PositionedFloats() const {
     return positioned_floats_;
@@ skipping 14 matching lines @@
 
 DEFINE_TYPE_CASTS(NGPhysicalBoxFragment,
                   NGPhysicalFragment,
                   fragment,
                   fragment->Type() == NGPhysicalFragment::kFragmentBox,
                   fragment.Type() == NGPhysicalFragment::kFragmentBox);
 
 }  // namespace blink
 
 #endif  // NGPhysicalBoxFragment_h